1. Field of the Invention
The present invention pertains to a system and method for drilling deviated or generally horizontally extending wellbores and completing multiple wells from a single generally vertical wellbore.
2. Background
The development of techniques for drilling relatively high angle deviated wells from a generally vertical wellbore has provided several advantages in recovering oil and gas from subterranean formations. One or more deviated or generally horizontal wellbores may be drilled from single generally vertical wellbore to provide wellbores which: (a) reach irregular reservoirs without additional wells being drilled from the surface, (b) limit the invasion of unwanted formation fluids, (c) penetrate natural vertical fractures and (d) improve production from various types of formations or reservoirs.
However, one shortcoming of prior art multiple wellbores pertains to the lack of separation of one wellbore from the other to prevent commingling of fluids or to provide for treatment of one wellbore while precluding the application of the same treatment to other wellbores extending from or comprising part of the single vertical wellbore. It is to this end that the present invention has been developed with the provision of an improved system and method for completing multiple wells from a single generally vertical wellbore. Although the terms vertical, deviated and horizontal are used herein for convenience, those skilled in the art will recognize that the system and method of the invention may be employed with respect to wells which extend in directions other than generally vertical or horizontal.